What Is a Liquid Mixer?
A liquid mixer is used for industrial blending and can be found in a variety of applications. Mixing can be a simple process like mixing concrete or it can be more complex, such as dispersing gases.
Mixers keep liquids moving at all times, which is crucial for achieving consistent products. They also help suspend sinking solids and create emulsions.
Flow
Mixing liquids with different viscosities is one of the most common industrial processes. To achieve the right mixing results, we need to know how the fluid moves inside the tank and what effect it has on other components within the mixture. We can use advanced simulation software to help us understand this flow.
The type of mixer we need depends on what we are trying to accomplish. For example, if we are mixing two liquids that are chemically identical but have different viscosities, we would need Labeling Machine to select a mixer with an impeller that is sized appropriately for the specific application. This will ensure that the liquids are pumped at a rate that can be maintained in heated (jacketed) tanks.
On the other hand, if we are mixing powdered solids into liquid, a strong rotational flow may not be desirable. This is because the rotational motion will pull the particles into the liquid instead of dispersing them or suspending them. This can cause agglomeration of the solids or even force them to sink into the bottom of the tank.
Viscosity
A fluid’s resistance to flow is called viscosity. It precisely quantifies the internal friction that occurs between layers of a fluid as they move past each other during movement. The more viscous a liquid, the more intermolecular forces produce internal friction between its molecules and the faster it resists motion. Viscosity applies to both liquids and gases, although the molecular structure of gases causes very little internal friction during movement, so they tend to flow more readily than liquids.
The more strongly bonded the molecules in a liquid, the higher its viscosity. Hydrogen bonding is especially strong, so glycerin has a much higher viscosity than water. Viscosity can be measured by dropping a spherical metal ball into the liquid and measuring the time it takes to travel a given distance. The higher the viscosity, the more the balls will travel slowly.
Shear
Inline high shear mixers can create suspensions, emulsions or granular products. In addition to mixing and dispersing they can help break down and reduce particle size. They can also bind solid materials into denser agglomerates or create emulsions by dispersing two immiscible liquids such as oil and water.
These mixers use a precision engineered rotor stator workhead to achieve results unobtainable with simple stirrers or agitators. As the rotor spins it forces the material into the gap between the rotor and stator, subjecting it to intense mechanical shear and hydraulic shear. This three-stage mixing/homogenising process quickly delivers a uniform product.
The shear of a non-Newtonian fluid is time-dependent and can either thin or thicken the mixture. This is known as thixotropy and is critical for achieving a quality product.
Shear can be increased or decreased by changing the structural parameters of the mixer such as rotor speed, blade design, teeth number and flow rate. The shear of a non-Newtonian liquid can also increase or decrease by increasing the concentration of particles and temperature. These factors can affect the shear of a product and influence the properties of its dispersions and emulsions.
Vortex
In physics, a vortex refers to a circular motion that rotates inward. These circular motions can also cause the formation of spiral pathlines, called streamlines. This appearance is often mistaken for the flow of smoke or ink in a cloud, but these paths are actually closed loops in which particles move continuously.
Vortex mixers can mix liquids with different viscosities, as well as solids in a liquid state. They can achieve this by operating at a specific speed or rpm that creates a circular motion within the sample. These types of mixers are commonly used in labs to re-suspend cells, mix cell cultures, or prepare samples for DNA extraction.
There are many variations of vortex mixers to fit different laboratory needs. These include different speed ranges, mixing capacity, and special features. For example, Next Day Science offers a multi-tube vortex mixer that can mix up to six flasks or tubes at once, as well as an analog model designed for more controlled mixing. They can also come with a wide variety of attachments, including foam test tube inserts, microtiter plates, and universal platforms.
Energy
The energy required to drive the mixing process in a liquid mixer can vary depending on the type of mixture, its viscosity and its temperature. The higher the viscosity, the more energy is needed to drive the fluid. In addition, some fluids “act” less viscous when shear is applied to them, which can reduce the amount of energy that is required to mix a substance.
A liquid mixer can be used for a number of applications, including blending, labeling machine manufacturer homogenizing and emulsifying. Silverson Machines offers a wide range of dynamic, inline mixers that can handle everything from low shear to simulate manual stirring all the way up to high shear for emulsifying and homogenizing.
Multiphase mixing is a chemical process in which solids, liquids and gases are combined in one step. This can be done for a variety of purposes, such as in fuel production where solid biofuels are mixed with water to create ethanol; or as part of a fermentation process, in which solid microbes and their associated gases must be combined with a liquid medium.